1. The Field of the Invention
The present invention is related to pyrotechnic smoke producing compositions. More particularly, the present invention is related to generally non-toxic and non-corrosive smoke producing compositions which incorporate, as a smoke producing agent, at least one aliphatic dicarboxylic acid.
2. Technical Background
In various contexts it is desirable to have the capability of producing smoke for a number of different types of use. For example, the ability to produce smoke at a particular location may provide the basis for a remote signaling system. Such a system may have application in search and rescue operations and in military exercises. Smoke of a particular color and density may also be desirable for training purposes. For example, in order to train fire fighters it would be advantageous to simulate specific types of fire conditions. For individuals working in a fire-prone environment, such as on an aircraft or ship, it would also be desirable to have the capability of simulating fire in order to provide a realistic fire drill.
Smoke can be used as a marker for various purposes. A smoke marker can be seen from substantial distances, either from the ground for from the air. Accordingly, a smoke marker would be useful in military operations, search and rescue, certain types of industrial projects, or in any other situation in which it is important to find and mark a particular location.
In the military context, the need for smoke producing devices and compositions is well appreciated. As mentioned above, smoke can be used as a marker. Smoke may be used to mark a particular target, or it may be used as a marker in determining the position of specific personnel and equipment.
Smoke may also be used to obscure vision. A shield of smoke may be very helpful in conducting military operations in order to prevent adverse forces from obtaining a clear view of the operations. For example, it may be desirable to use a vision obscuring smoke in order to move troops and equipment under at least partial cover.
Various types of smoke producing compositions and devices are presently known, however, most such smoke producing compositions have severe limitations. One of the limitations is that of toxicity. Many smoke producing compositions incorporate materials which are severely toxic or are irritants when subjected to the heat necessary to produce smoke. The problem of toxicity and irritation to people is clearly a limitation in several respects. Not only does it increase the potential for injury, but it may dictate the use of additional specialized equipment, such a respiratory protection. This type of equipment is expensive, and in the situations such as training exercises, may detract from the ability to simulate actual conditions.
A related problem is the effect of smoke producing compositions on equipment and supplies. In addition to being toxic and irritating to people, conventional smoke producing compositions are corrosive and damaging to both mechanical and electronic equipment. It will be appreciated that this is a major disadvantage in the operational context in which a smoke producer is typically employed. Smoke producers are usually employed in field operations which involve the use of precision electronic and mechanical equipment, that may be damaged by the corrosive exhaust of such smoke producing agents. Accordingly, the use of corrosive and damaging chemical compositions is a severe limitation.
One example of a widely known smoke producing composition employs a reaction between hexachloroethane and zinc to produce zinc chloride. However, the reaction products from this reaction are very toxic, limiting the usefulness and applicability of the composition. Another common smoke producing composition employs phosphorous, and phosphorous compounds. These chemicals, however, are known to be extreme irritants when reacted to produce smoke. In addition, phosphorous reactions typically produce intense heat which is a further hazard and limitation of this type of material.
Another class of smoke producing compounds comprise aromatic organic materials. Various types of aromatics are known to produce smoke. Indeed, certain aromatics produce smoke of intense color and have been used widely in military applications. The problem with aromatic compounds, however, it that they are also generally toxics and irritants. The reaction products of aromatic compounds are also corrosive and toxic.
In summary, there is a need for effective smoke producing compositions. This need exists in military and civilian operations. However, many smoke producing compositions presently used are difficult to handle. Many such compositions are toxic and irritating, and require special precautions during use. Many such compositions are corrosive and damaging to both electronic and mechanical equipment. Finally, some such compositions produce an excess of heat and flame, again limiting there usefulness and requiring that additional safety measures be taken. For these reasons, conventional smoke producing compositions are found to be inadequate.
As a result, it would be a significant advancement in the art to provide a smoke producing composition which was capable of overcoming the limitations in the existing art. In particular, it would be an advancement in the art to provide a smoke producing composition which was generally non-toxic and non-corrosive. It would be a related advantage in the art to provide such a composition which did not incorporate toxic or irritating materials such as zinc, phosphorous, and aromatic organic compounds. It would be another advancement in the art to provide smoke producing compositions which were simple to manufacture and use, but were still effective smoke producers.
Such compositions are disclosed and claimed herein.